<?php
/**
 * This file houses the MysqliUtility class.
 *
 * Copyright (c) 2010, Kalkomey Enterprises, Inc.
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 * 
 * - Redistributions of source code must retain the above copyright notice, this list
 *   of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright notice, this 
 *   list of conditions and the following disclaimer in the documentation and/or other
 *   materials provided with the distribution.
 * - Neither the name of the Kalkomey Enterprises, Inc. nor the names of its 
 *   contributors may be used to endorse or promote products derived from this 
 *   software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 * @license http://www.opensource.org/licenses/bsd-license.php New BSD License
 * @copyright Copyright (c) 2010, Kalkomey Enterprises, Inc.
 * @link http://code.google.com/p/swerv
 * @package Framework
 * @subpackage Library
 */

if (!defined('MYSQL_CONN_TYPE_READ_ONLY')) {
	/**
	 * Flag for read only connection.
	 */
	define('MYSQL_CONN_TYPE_READ_ONLY', 1);
}

if (!defined('MYSQL_CONN_TYPE_READ_WRITE')) {
	/**
	 * Flag for read write connection.
	 */
	define('MYSQL_CONN_TYPE_READ_WRITE', 2);
}

if (!defined('MYSQL_CONN_TYPE_SCHEMA')) {
	/**
	 * Flag for schema connection.
	 */
	define('MYSQL_CONN_TYPE_SCHEMA', 3);
}


/**
 * The MysqlUtility class is used to obtain a connection to the database using the ExceptionalMysqli class.
 *
 * @package Framework
 * @subpackage Library
 */
class MysqliUtility {

	public static function getConnectionData($type) {
		global $mysqlTest, $mysqlSlaves, $mysqlMasters;
		if (IS_TEST === true) {
		 	return $mysqlTest;
		}
		switch ($type) {
			case MYSQL_CONN_TYPE_READ_ONLY:
				return $mysqlSlaves[rand(0, (count($mysqlSlaves) - 1))];
			case MYSQL_CONN_TYPE_SCHEMA:
				return $mysqlMasters[0];
			default:
				return $mysqlMasters[rand(0, (count($mysqlMasters) - 1))];
		}
		
	}

	/**
	 * Obtains a read-only connection to a MySQL slave database.
	 *
	 * @uses $mysqlSlaves
	 *
	 * @return ExceptionalMysqli
	 */
	public static function getReadOnlyConnection() {
		$data = MysqliUtility::getConnectionData(MYSQL_CONN_TYPE_READ_ONLY);
		$conn = new ExceptionalMysqli($data['host'], $data['user'], $data['pass'], $data['name'], $data['port']);
		return $conn;
	}

	/**
	 * Obtains a read/write connection to a MySQL master database.
	 *
	 * @uses $mysqlMasters
	 *
	 * @return ExceptionalMysqli
	 */
	public static function getReadWriteConnection() {
		$data = MysqliUtility::getConnectionData(MYSQL_CONN_TYPE_READ_WRITE);
		$conn = new ExceptionalMysqli($data['host'], $data['user'], $data['pass'], $data['name'], $data['port']);
		return $conn;
	}

	/**
	 * Obtains a read only connection to the MySQL information_schema database.
	 *
	 * @uses $mysqlMasters
	 *
	 * @throws DatabaseConnectionException
	 *
	 * @return ExceptionalMysqli
	 */
	public static function getSchemaConnection() {
		$data = MysqliUtility::getConnectionData(MYSQL_CONN_TYPE_SCHEMA);
		$conn = new ExceptionalMysqli($data['host'], $data['user'], $data['pass'], 'information_schema', $data['port']);
		return $conn;
	}
}
